SMBC-NZP/MigConnectivity: v0.2.5

In this release, we sped up calcMC, especially for large numbers of sites.

We also made two minor extensions:

1. We made sure at least two target sites are included in each bootstrap sample in estMC, thus ensuring that inference is based on the desired number of bootstrap samples (you can't calculate MC without at least two target sites).
2. Added argument maxTries to estMC and estMantel, which provides a limit to how many times the functions will try to resample points within a single bootstrap run, to prevent them from running for days without ever producing results. This issue is usually caused by combinations of targetSites, geoBias, and geoVCov that generate most sample points outside targetSites.

And one minor bug fix: nSim wasn't being passed along in estMC, so setting it away from the default did nothing.